A method and system for predicting humidification capacity of a humidifier for a fuel cell

Abstract

The present invention provides a method and system for predicting the humidification capacity of a fuel cell humidifier, which belongs to the field of fuel cell technology and solves the problem that the existing technology cannot accurately predict the humidified gas output by the humidifier under different working conditions. The method includes: establishing an input of real-time data of gas state parameters at the dry and wet side inlets of the humidifier, and outputting predicted data of gas state parameters at the dry and wet side outlets of the humidifier, including the wet side orifice coefficient C of the humidifier. r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, and heat transfer coefficient U as the parameters to be calibrated in a humidifier physical model; obtain the experimental data of the gas state parameters at the inlet and outlet of the dry side and wet side of the humidifier, and determine the above-mentioned parameters to be calibrated in the humidifier physical model; according to the real-time data of the gas state parameters at the inlet of the dry side and wet side of the humidifier at the current moment, combined with the humidifier physical model, obtain the predicted data of the gas state parameters at the outlet of the dry side and wet side of the humidifier.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a method and system for predicting the humidification capacity of a humidifier for a fuel cell. Background Art

[0002] The chemical reactions within fuel cells that generate energy require a certain amount of water. A humidifier recovers moisture from the stack's exhaust to humidify the incoming gas. The required humidity of the incoming gas varies under different operating conditions, making it crucial to analyze the humidification performance of the humidifier under varying input parameters. Establishing a realistic physical model for the humidifier facilitates achieving stack water balance.

[0003] Existing technologies are unable to predict the humidity of the humidified gas output by the humidifier under different operating conditions. Overshoot or imbalance may occur during the dynamic load change of the fuel cell, resulting in the humidity of the gas entering the stack exceeding or falling below the humidity of the gas required by the stack. The humidification process of the humidifier cannot be accurately controlled, resulting in "flooding" or "membrane drying", which affects the life of the stack. Summary of the Invention

[0004] In view of the above analysis, the embodiments of the present invention aim to provide a method and system for predicting the humidification capacity of a fuel cell humidifier, so as to solve the problem that the existing technology cannot accurately predict the humidified gas output by the humidifier under different working conditions.

[0005] In one aspect, an embodiment of the present invention provides a method for predicting the humidification capacity of a fuel cell humidifier, comprising the following steps:

[0006] The input is the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier, and the output is the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier, including the wet side orifice coefficient C of the humidifier. r _ s , Dry side orifice coefficient C r_t , mass transfer coefficient D, heat transfer coefficient U as the physical model of the humidifier to be calibrated;

[0007] Obtaining test data of gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier, and determining the above-mentioned parameters to be calibrated in the humidifier physical model;

[0008] The real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the current moment are obtained, and input into the humidifier physical model after the calibration parameters are determined, and the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier are obtained.

[0009] The beneficial effects of the above technical solution are as follows: A method for predicting the humidification capacity of a humidifier for a fuel cell is proposed to solve the problem that the existing technology cannot accurately predict the humidified gas output by the humidifier under different working conditions. The constructed humidifier physical model is calibrated through experimental data to make it consistent with the actual complex working conditions. In particular, the humidifier physical model can be used to predict the humidity change trend of the gas entering the stack under dynamic working conditions. The influence of the gas state parameters at the inlet on the humidity of the gas entering the stack can also be studied, so that corresponding measures can be taken to adjust the humidity of the gas entering the stack, which can avoid the impact of "flooding" or "membrane drying" on the life of the fuel cell stack.

[0010] Based on the further improvement of the above method, the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier respectively include gas flow, gas temperature, gas pressure, and gas humidity;

[0011] The following steps are also included to verify the correctness of the humidifier physical model:

[0012] After the parameters to be calibrated in the humidifier physical model are determined, new test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier are obtained again;

[0013] The new test data of the gas state parameters at the inlet of the dry side and the wet side are input into the humidifier physical model after the calibration parameters are determined, and new predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier are obtained;

[0014] Identifying whether the new predicted data of the gas state parameters at the outlets of the dry side and the wet side of the humidifier are consistent with the corresponding new experimental data of the gas state parameters at the outlets of the dry side and the wet side, so as to determine the correctness of the humidifier physical model;

[0015] The step of obtaining test data of gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier further includes:

[0016] A gas flow meter, a gas temperature sensor, a gas pressure sensor, and a gas humidity sensor are respectively arranged on the inner walls of the input and output pipes on the dry and wet sides of the humidifier;

[0017] A bench test is conducted on the humidifier equipped with the above-mentioned sensors to obtain the gas flow rate, gas temperature, gas pressure, and gas humidity at the inlet and outlet of the dry side and wet side of the humidifier, respectively, as the test data of the gas state parameters at the inlet and outlet of the dry side and wet side of the humidifier;

[0018] The humidifier physical model includes:

[0019]

[0020] in

[0021] h in1 =c p ·T in1 , h in2 =c p ·T in2

[0022] h out1 =c p ·T out1 , h out2 =c p ·T out2

[0023] h tr =c p ·[1 / 2(T in2 +T out2 )-1 / 2(T out1 +T in1 )]

[0024] u1=c v ·T in1

[0025] u2=c v ·T in2

[0026] W1=W in1 -W out1 +W vap,tr

[0027] W2=W in2 -W out2 -W vap,tr

[0028]

[0029] ΔT=1 / 2[(T in2 +T out2 )-(T out1 +T in1 )]

[0030]

[0031]

[0032] Where W out1 is the gas flow prediction data at the dry side outlet of the humidifier, W in1 is the real-time data of gas flow at the dry side inlet of the humidifier, W out2 is the gas flow prediction data at the wet side outlet of the humidifier, W in2 is the real-time data of gas flow at the wet side inlet of the humidifier, h tr is the gas enthalpy of water vapor, is the heat transferred from the wet side to the dry side, W vap,tr is the water vapor mass transfer, W1 is the dry side gas flow, W2 is the wet side gas flow, c p is the specific heat capacity of gas at constant pressure, c v is the constant volume specific heat capacity of gas, m is the gas mass, U is the heat transfer coefficient, A hum is the total membrane area of ​​the humidifier, ΔT is the temperature difference between the dry side and the wet side, M vap is the molar mass of water vapor, D is the mass transfer coefficient, C r_s is the wet side orifice coefficient, C r_t is the dry side orifice coefficient, C s is the wet side water concentration, C t is the water concentration on the dry side, ρ is the density of the membrane, M mem is the equivalent mass of the proton exchange membrane, λ1 is the water content on the dry side, λ2 is the water content on the wet side, t mem is the thickness of the film, a1 is the predicted data of gas humidity at the dry side outlet of the humidifier, a2 is the predicted data of gas humidity at the wet side outlet of the humidifier, T in1 is the real-time data of gas temperature at the dry side inlet of the humidifier, T in2 is the real-time data of gas temperature at the wet side inlet of the humidifier, T out1 is the predicted data of gas temperature at the dry side outlet of the humidifier, T out2 is the predicted data of gas temperature at the wet side outlet of the humidifier, P in1 is the real-time data of gas pressure at the dry side inlet of the humidifier, P in2 is the real-time data of gas pressure at the wet side inlet of the humidifier, P out1 is the predicted data of the air pressure at the dry side outlet of the humidifier, P out2 is the predicted data of air pressure at the wet side outlet of the humidifier, P sub1 The preset pressure of the air entering the pile, P sub2 The preset pressure of the air leaving the stack, P vap1 is the water vapor pressure at the dry side outlet of the humidifier, P vap2 is the water vapor pressure at the wet side outlet of the humidifier, P sat1 is the saturated vapor pressure corresponding to the gas temperature at the dry side outlet of the humidifier, P sat2 is the saturated water vapor pressure corresponding to the gas temperature at the wet side outlet of the humidifier, V1 is the volume of the dry side of the humidifier, V2 is the volume of the wet side of the humidifier, n1 is the amount of water vapor substance on the dry side of the humidifier, n2 is the amount of water vapor substance on the wet side of the humidifier, R is the ideal gas constant, P sat_in1 is the saturated vapor pressure corresponding to the gas temperature at the dry side inlet of the humidifier, P sat_in2 RH is the saturated vapor pressure corresponding to the gas temperature at the wet side inlet of the humidifier, in1 The real-time data of gas humidity at the dry side inlet of the humidifier, RHin2 Real-time data of gas humidity at the wet side inlet of the humidifier, t is the current time, t deltat For the previous moment;

[0033] The step of obtaining the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier, and determining the parameters to be calibrated in the physical model of the humidifier further includes:

[0034] Obtain the gas flow rate, gas temperature, gas pressure, and gas humidity at the inlet and outlet of the dry side and the wet side of the humidifier as the gas state parameter test data at the inlet and outlet of the dry side and the wet side of the humidifier;

[0035] The determination is based on the gas state parameter test data at the inlet and outlet of the dry side and wet side of the humidifier as input, and includes the wet side orifice coefficient C r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, heat transfer coefficient U to be calibrated parameters of the humidifier humidification capacity objective function model;

[0036] The iterative change rule of each of the above-mentioned parameters to be calibrated is set, and the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier are brought into the above-mentioned humidifier humidification capacity objective function model for iteration until the parameters to be calibrated that minimize the output value of the humidifier humidification capacity objective function model are obtained.

[0037] Furthermore, the humidifier humidification capacity objective function model includes:

[0038] y(C r_t ,C r_s ,D,U)

[0039] =sqrt{[W out10 -W out1 (C r_t ,C r_s ,D,U)] 2 +[W out20 -W out2 (C r_t ,C r_s ,D,U)] 2 +[P out10 -P out1 (C r_t ,C r_s ,D,U)] 2 +[P out20 -P out2 (C r_t ,C r_s ,D,U)] 2 +[a 10 -a1(C r_t ,Cr_s ,D,U)] 2 +[a 20 -a2(C r_t ,C r_s ,D,U)] 2 +[T out10 -T out1 (C r_t ,C r_s ,D,U)] 2 +[T out20 -T out2 (C r_t ,C r_s ,D,U)] 2}

[0040] Where, y(C r_s , C r_t , D, U) is the objective function, W out10 is the gas flow test data at the dry side outlet, W out1 (C r_s , C r_t , D, U) is the gas flow prediction data at the dry side outlet obtained by the humidifier physical model, W out20 is the test data of gas flow rate at wet side outlet, W out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas flow rate obtained by the humidifier physical model, P out10 is the gas pressure test data at the dry side outlet, P out1 (C r_s , C r_t , D, U) is the dry side outlet gas pressure prediction data obtained by the humidifier physical model, P out20 is the wet side outlet gas pressure test data, P out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas pressure obtained by the humidifier physical model, a 10 is the test data of gas humidity at the dry side outlet, a1(C r_s , C r_t , D, U) are the predicted data of gas humidity at the dry side outlet obtained by the humidifier physical model, a 20 is the test data of gas humidity at the wet side outlet, a2(C r_s , C r_t , D, U) are the predicted data of wet side outlet gas humidity obtained by the humidifier physical model, T out10 is the test data of gas temperature at the dry side outlet, T out1 (C r_s , C r_t, D, U) is the predicted data of gas temperature at the dry side outlet obtained by the humidifier physical model, T out20 is the test data of wet side outlet gas temperature, T out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas temperature obtained by the humidifier physical model, and sqrt{} is the square root function.

[0041] Furthermore, the step of setting an iterative change rule for each of the above parameters to be calibrated, bringing the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier into the above humidifier humidification capacity objective function model for iteration until the parameter to be calibrated that minimizes the output value of the humidifier humidification capacity objective function model is obtained further includes:

[0042] Set the initial values ​​of all parameters to be calibrated, the change range of each iteration, and the maximum number of iterations;

[0043] The gas state parameter test data at the dry side and wet side inlet of the humidifier are brought into the humidifier physical model with the parameters to be calibrated, and the gas state parameter prediction data at the dry side and wet side outlet of the humidifier are obtained in each iteration;

[0044] The predicted data of the gas state parameters at the dry side and wet side outlets of the humidifier and their corresponding test data are respectively input into the humidification capacity objective function model of the humidifier containing the above parameters to be calibrated for iterative calculation;

[0045] Identify whether the absolute value of the difference between the objective function of the previous and next iterations is less than or equal to the set precision, or the number of iterations is greater than or equal to the maximum number of iterations. If so, stop the iteration and execute the next step. Otherwise, continue the iteration.

[0046] Obtain the smaller value of the two objective functions at the time of stopping iteration, and use the corresponding undetermined parameter value as the final calibrated undetermined parameter value.

[0047] Furthermore, the setting accuracy is 10 -3 Above, the maximum number of iterations is 10 -4 above.

[0048] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0049] 1. The humidifier physical model built through calibration can more accurately study the impact of changes in gas parameters at the inlet on the humidification capacity of the humidifier, and predict the changes in the humidification capacity of the humidifier under dynamic conditions, so that corresponding measures can be taken to adjust the humidity of the gas entering the reactor.

[0050] 2. Applicable to different operating conditions and complex vehicle operating conditions, especially under dynamic load changes. The humidifier in the existing solution has a delayed response and cannot be directly controlled, which may cause the humidity of the gas entering the stack to fail to meet or exceed the required humidity of the gas entering the stack. By conducting bench tests on the humidifier, the inlet and outlet gas parameters of the dry and wet sides are obtained, and the parameters of the constructed humidifier physical model are calibrated based on the experimental data. The final parameter values ​​are determined by minimizing the objective function. The calibrated humidifier physical model is then verified using the new experimental data to determine the accuracy of the model.

[0051] 3. Based on the calibrated physical model of the humidifier, the humidification capacity of the humidifier under different inlet gas parameters is explored. The dynamic response characteristics of the humidifier can be studied through the physical model, and the humidity changes can be predicted to formulate a control strategy to adjust the humidity of the gas entering the stack, thereby avoiding the problem of "flooding" or "membrane drying" affecting the life of the fuel cell stack.

[0052] On the other hand, an embodiment of the present invention provides a system for predicting the humidification capacity of a fuel cell humidifier corresponding to the above method, comprising:

[0053] A parameter acquisition unit is used to obtain real-time data of gas state parameters at the inlet of the dry side and the wet side of the humidifier at the current moment and send it to the data analysis and prediction module;

[0054] The data analysis and prediction module is used to establish the input of the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier, and the output is the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier, including the wet side orifice coefficient C of the humidifier. r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, and heat transfer coefficient U as parameters to be calibrated for a humidifier physical model; obtaining test data of gas state parameters at the inlet and outlet of each of the dry side and the wet side of the humidifier, and determining the above-mentioned parameters to be calibrated in the humidifier physical model; obtaining real-time data of the gas state parameters at the inlet of each of the dry side and the wet side of the humidifier at the current moment, inputting the data into the humidifier physical model after the parameters to be calibrated are determined, and obtaining predicted data of the gas state parameters at the outlet of each of the dry side and the wet side of the humidifier, and sending the predicted data to the prediction result output unit;

[0055] The prediction result output unit is used to display the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the previous moment, as well as the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier.

[0056] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0058] Figure 1 A schematic diagram showing the steps of a method for predicting the humidification capacity of a fuel cell humidifier according to Example 1 is shown;

[0059] Figure 2 A schematic diagram showing the principle of the method for predicting the humidification capacity of a humidifier for a fuel cell in Example 2 is shown. DETAILED DESCRIPTION

[0060] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0061] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "first," "second," etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0062] Example 1

[0063] One embodiment of the present invention discloses a method for predicting the humidification capacity of a fuel cell humidifier, such as Figure 1 As shown, the following steps are included:

[0064] S1. Establish input as real-time data of gas state parameters at the inlet of the dry side and wet side of the humidifier, and output as predicted data of gas state parameters at the outlet of the dry side and wet side of the humidifier, including the wet side orifice coefficient C of the humidifier. r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, heat transfer coefficient U as the physical model of the humidifier to be calibrated;

[0065] Specifically, in addition to the physical model described in Example 2, the humidifier physical model can be an artificial neural network or other function model. For example, assuming that the real-time data of the gas state parameters at the dry side and the wet side inlet is x, the humidifier physical model is the predicted data of the gas state parameters at the dry side and the wet side outlet, respectively, X = F (C r_s , C r_t , D, U, x); where X is related to the wet side orifice coefficient C r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, heat transfer coefficient U are related, and F() is calibrated through experiments;

[0066] S2. Obtain test data of gas state parameters at the inlet and outlet of the dry side and wet side of the humidifier, and determine the above parameters to be calibrated in the humidifier physical model;

[0067] Specifically, a bench test is performed on the humidifier, and gas state sensors are arranged at the inlet and outlet of each of the dry side and the wet side of the humidifier to obtain test data of gas state parameters at the inlet and outlet of each of the dry side and the wet side of the humidifier; the test data is brought into the humidifier physical model established in step S1, and its coefficients are calibrated (determined);

[0068] S3. Obtain the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the current moment, input them into the humidifier physical model after the calibration parameters are determined, and obtain the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier.

[0069] It should be noted that the wet side orifice coefficient C r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, and heat transfer coefficient U are the influencing factors of the gas state parameters. The parameters to be calibrated of the constructed humidifier physical model are calibrated through experimental data to make them consistent with the actual situation. With the help of the physical model, the influence of the gas state parameters at the inlet on the humidity of the gas entering the pile can be studied, and the changing trend of the humidity of the gas entering the pile under dynamic conditions can also be predicted.

[0070] Wet side orifice coefficient C r_s , Dry side orifice coefficient C r_t is the pipeline orifice flow coefficient, which can be obtained through theoretical calculation or experimental data calibration.

[0071] The mass transfer coefficient, D, is the mass transfer rate divided by the mass transfer area, then divided by the mass transfer driving force. The mass transfer area refers to the interphase contact area. The driving force can be calculated as the average value of various concentration or pressure differences.

[0072] The heat transfer coefficient U refers to the amount of heat transferred through an area of ​​1 square meter in 1 second when the air temperature difference on both sides of the enclosure structure is 1 degree (K, ℃) under stable heat transfer conditions. The unit is watt / (square meter·degree) (W / ㎡·K, where K can be replaced by ℃).

[0073] Compared with the existing technology, this embodiment proposes a method for predicting the humidification capacity of a humidifier for a fuel cell, which is used to solve the problem that the existing technology cannot accurately predict the humidified gas output by the humidifier under different working conditions. The constructed humidifier physical model is calibrated through experimental data to make it consistent with the actual complex working conditions. In particular, the humidifier physical model can be used to predict the humidity change trend of the gas entering the stack under dynamic working conditions. The influence of the gas state parameters at the inlet on the humidity of the gas entering the stack can also be studied, so that corresponding measures can be taken to adjust the humidity of the gas entering the stack, thereby avoiding the impact of "flooding" or "membrane drying" on the life of the fuel cell stack.

[0074] Example 2

[0075] Based on the method of Example 1, an improvement is made. In step S1, the gas state parameters at the inlet and outlet of the dry side and wet side of the humidifier include gas flow rate, gas temperature, gas pressure, and gas humidity. Specifically, flow meters, temperature sensors, humidity sensors, and pressure sensors are installed at the dry side inlet, dry side outlet, wet side inlet, and wet side outlet of the humidifier to measure and obtain test data.

[0076] Preferably, the method further comprises a step S2' of verifying the correctness of the humidifier physical model. Wherein, the step S2' further comprises:

[0077] S21 'after the humidifier physical model parameters to be calibrated are determined, the humidifier dry side and wet side are obtained again at the inlet and outlet of the gas state parameters of the new test data;

[0078] S22 'the dry side and wet side of the respective inlet gas state parameters of the new test data, input to be calibrated parameters after the humidifier physical model, the humidifier dry side and wet side of the respective outlet gas state parameters of the new prediction data;

[0079] S23'. Identify whether the newly predicted gas state parameter data at the dry and wet side outlets of the humidifier are consistent with the corresponding newly tested gas state parameter data at the dry and wet side outlets, thereby determining the correctness of the humidifier physical model. Specifically, if they are consistent, the humidifier physical model is correct; otherwise, the model must be re-modeled.

[0080] Specifically, m% of the test data can be used to calibrate the parameters to be calibrated, and then the accuracy of the humidifier physical model after calibration can be verified based on another (1-m%) set of test data. That is, after determining the values ​​of the parameters to be calibrated, the other (1-m%) sets of dry-side and wet-side inlet gas test data are substituted into the humidifier physical model to calculate the predicted data for the dry-side and wet-side outlets of the humidifier. The predicted data are then compared with the test data to verify the accuracy of the humidifier physical model.

[0081] Preferably, in step S1, the humidifier physical model includes a model in the following formula:

[0082]

[0083] in

[0084] h in1 =c p ·T in1 , h in2 =c p ·T in2

[0085] h out1 =c p ·T out1 , h out2 =c p ·T out2

[0086] h tr =c p ·[1 / 2(T in2 +T out2 )-1 / 2(T out1 +T in1 )]

[0087] u1=c v ·T in1

[0088] u2=c v ·T in2

[0089] W1=W in1 -W out1 +W vap,tr

[0090] W2=W in2 -W out2 -W vap,tr

[0091] The heat transfer process of gas from wet side to dry side can be expressed as:

[0092]

[0093] ΔT=1 / 2[(T in2 +T out2 )-(T out1 +T in1 )]

[0094]

[0095] The water vapor mass transfer during the humidification process of the wet side to the dry side gas of the humidifier is:

[0096]

[0097]

[0098] Where W out1 is the gas flow prediction data at the dry side outlet of the humidifier, W in1 is the real-time data of gas flow at the dry side inlet of the humidifier, W out2 is the gas flow prediction data at the wet side outlet of the humidifier, W in2 is the real-time data of gas flow at the wet side inlet of the humidifier, h tr is the gas enthalpy of water vapor, is the heat transferred from the wet side to the dry side, W vap,tr is the water vapor mass transfer, W1 is the dry side gas flow, W2 is the wet side gas flow, c p is the specific heat capacity of gas at constant pressure, c v is the constant volume specific heat capacity of gas, m is the gas mass, U is the heat transfer coefficient, A hum is the total membrane area of ​​the humidifier, ΔT is the temperature difference between the dry side and the wet side, M vap is the molar mass of water vapor, D is the mass transfer coefficient, C r_s is the wet side orifice coefficient, C r_t is the dry side orifice coefficient, C s is the wet side water concentration, C t is the water concentration on the dry side, ρ is the density of the membrane, M mem is the equivalent mass of the proton exchange membrane, λ1 is the water content on the dry side, λ2 is the water content on the wet side, t mem is the thickness of the film, a1 is the predicted data of gas humidity at the dry side outlet of the humidifier, a2 is the predicted data of gas humidity at the wet side outlet of the humidifier, T in1 is the real-time data of gas temperature at the dry side inlet of the humidifier, T in2 is the real-time data of gas temperature at the wet side inlet of the humidifier, T out1 is the predicted data of gas temperature at the dry side outlet of the humidifier, T out2 is the predicted data of gas temperature at the wet side outlet of the humidifier, P in1 is the real-time data of gas pressure at the dry side inlet of the humidifier, P in2 is the real-time data of gas pressure at the wet side inlet of the humidifier, Pout1 is the predicted data of the air pressure at the dry side outlet of the humidifier, P out2 is the predicted data of air pressure at the wet side outlet of the humidifier, P sub1 The preset pressure of the air entering the pile, P sub2 The preset pressure of the air leaving the stack, P vap1 is the water vapor pressure at the dry side outlet of the humidifier, which is related to the gas humidity at the dry side outlet. vap2 is the water vapor pressure at the wet side outlet of the humidifier, which is related to the gas humidity at the wet side outlet. sat1 is the saturated vapor pressure corresponding to the gas temperature at the dry side outlet of the humidifier, P sat2 is the saturated water vapor pressure corresponding to the gas temperature at the wet side outlet of the humidifier, V1 is the volume of the dry side of the humidifier, V2 is the volume of the wet side of the humidifier, n1 is the amount of water vapor substance on the dry side of the humidifier, n2 is the amount of water vapor substance on the wet side of the humidifier, R is the ideal gas constant, P sat_in1 is the saturated vapor pressure corresponding to the gas temperature at the dry side inlet of the humidifier, P sat_in2 RH is the saturated vapor pressure corresponding to the gas temperature at the wet side inlet of the humidifier, in1 The real-time data of gas humidity at the dry side inlet of the humidifier, RH in2 Real-time data of gas humidity at the wet side inlet of the humidifier, t is the current time, t deltat For the previous moment, To differentiate u1, To differentiate u2.

[0099] After determining the humidifier physical model, it is necessary to determine the value ranges of the four parameters to be calibrated. Specifically, the order of magnitude of the parameters to be calibrated is calculated based on the humidifier physical model, so as to determine the value range as the parameter value area of ​​the iterative algorithm.

[0100] Preferably, step S2 further comprises:

[0101] S21. A gas flow meter, a gas temperature sensor, a pressure sensor, and a gas humidity sensor are arranged on the inner wall of the input and output pipes on the dry and wet sides of the humidifier;

[0102] S22. Bench test the humidifier equipped with the above-mentioned sensors to obtain the gas flow rate, gas temperature, gas pressure, and gas humidity at the inlet and outlet of the dry side and wet side of the humidifier, respectively, as the test data of the gas state parameters at the inlet and outlet of the dry side and wet side of the humidifier;

[0103] S23. Determine the input of the gas state parameter test data at the inlet and outlet of the dry side and wet side of the humidifier, including the wet side orifice coefficient C r_s , Dry side orifice coefficient C r_t, mass transfer coefficient D, heat transfer coefficient U to be calibrated parameters of the humidifier humidification capacity objective function model;

[0104] S24. Set the iterative change rule of each of the above parameters to be calibrated, and bring the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier into the above humidifier humidification capacity objective function model for iteration until the parameter to be calibrated that minimizes the output value of the humidifier humidification capacity objective function model is obtained.

[0105] Preferably, the humidification capacity objective function model of the humidifier in step S23 includes:

[0106] y(C r_t ,C r_s ,D,U)

[0107] =sqrt{[W out10 -W out1 (C r_t ,C r_s ,D,U)] 2 +[W out20 -W out2 (C r_t ,C r_s ,D,U)] 2 +[P out10 -P out1 (C r_t ,C r_s ,D,U)] 2 +[P out20 -P out2 (C r_t ,C r_s ,D,U)] 2 +[a 10 -a1(C r_t ,C r_s ,D,U)] 2 +[a 20 -a2(C r_t ,C r_s ,D,U)] 2 +[T out10 -T out1 (C r_t ,C r_s ,D,U)] 2 +[T out20 -T out2 (C r_t ,C r_s ,D,U)] 2}

[0108] Where, y(C r_s , C r_t , D, U) is the objective function, Wout10 is the gas flow test data at the dry side outlet, W out1 (C r_s , C r_t , D, U) is the gas flow prediction data at the dry side outlet obtained by the humidifier physical model, W out20 is the test data of gas flow rate at wet side outlet, W out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas flow rate obtained by the humidifier physical model, P out10 is the gas pressure test data at the dry side outlet, P out1 (C r_s , C r_t , D, U) is the dry side outlet gas pressure prediction data obtained by the humidifier physical model, P out20 is the wet side outlet gas pressure test data, P out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas pressure obtained by the humidifier physical model, a 10 is the test data of gas humidity at the dry side outlet, a1(C r_s , C r_t , D, U) are the predicted data of gas humidity at the dry side outlet obtained by the humidifier physical model, a 20 is the test data of gas humidity at the wet side outlet, a2(C r_s , C r_t , D, U) are the predicted data of wet side outlet gas humidity obtained by the humidifier physical model, T out10 is the test data of gas temperature at the dry side outlet, T out1 (C r_s , C r_t , D, U) is the predicted data of gas temperature at the dry side outlet obtained by the humidifier physical model, T out20 is the test data of wet side outlet gas temperature, T out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas temperature obtained by the humidifier physical model, and sqrt{} is the square root function.

[0109] Preferably, step S24 further includes:

[0110] S241. Set the initial values ​​of all parameters to be calibrated, the change range of each iteration, and the maximum number of iterations;

[0111] S242. The gas state parameter test data at the dry side and wet side inlet of the humidifier are brought into the humidifier physical model with the parameter changes to be calibrated, and the gas state parameter prediction data at the dry side and wet side outlet of the humidifier are obtained for each iteration;

[0112] Specifically, the test data of the gas state parameters at the inlet of the dry side and wet side of the humidifier are input into the humidifier physical model with set initial values ​​to obtain the first set of gas state prediction data for the dry side and wet side of the humidifier; the change amplitude of each iteration of the parameter to be calibrated is set, and the test data of the gas state parameters at the inlet of the dry side and wet side of the humidifier are sequentially input into the humidifier physical model after the parameter to be calibrated is changed to obtain each set of gas state prediction data for the dry side and wet side of the humidifier;

[0113] S243. The predicted data of the gas state parameters at the dry side and wet side outlets of the humidifier and their corresponding test data are respectively input into the humidification capacity objective function model of the humidifier including the above parameters to be calibrated for iterative calculation;

[0114] S244. Identify whether the following two iterative stopping conditions are met. The first condition is whether the absolute value of the difference between the objective functions of the two iterations is less than or equal to the set accuracy. For example, y(n)-y(n-1)≤10 -3 , y is the objective function, n is the number of iterations; the second condition is that the number of iterations is greater than or equal to the maximum number of iterations. If one of the conditions is met, stop the iteration and execute the next step, otherwise, continue the iteration;

[0115] S245. Obtain the smaller value of the two objective functions at the time of stopping iteration, and use the corresponding undetermined parameter value as the final calibration undetermined parameter value. Figure 2 As shown, but not limited to Figure 2 The content shown.

[0116] Preferably, the precision is set to 10 -3 , the maximum number of iterations is 10 -4 .

[0117] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0118] 1. The humidifier physical model built through calibration can more accurately study the impact of changes in gas parameters at the inlet on the humidification capacity of the humidifier, and predict the changes in the humidification capacity of the humidifier under dynamic conditions, so that corresponding measures can be taken to adjust the humidity of the gas entering the reactor.

[0119] 2. Applicable to different operating conditions and complex vehicle operating conditions, especially under dynamic load changes. The humidifier in the existing solution has a delayed response and cannot be directly controlled, which may cause the humidity of the gas entering the stack to fail to meet or exceed the required humidity of the gas entering the stack. By conducting bench tests on the humidifier, the inlet and outlet gas parameters of the dry and wet sides are obtained, and the parameters of the constructed humidifier physical model are calibrated based on some experimental data. The final parameter values ​​are determined by minimizing the objective function. The calibrated humidifier physical model is then verified using the remaining experimental data to determine the accuracy of the model.

[0120] 3. Based on the calibrated physical model of the humidifier, the humidification capacity of the humidifier under different inlet gas parameters is explored. The dynamic response characteristics of the humidifier can be studied through the physical model, and the humidity changes can be predicted to formulate a control strategy to adjust the humidity of the gas entering the stack, thereby avoiding the problem of "flooding" or "membrane drying" affecting the life of the fuel cell stack.

[0121] Example 3

[0122] The present invention also discloses a humidification capacity prediction system for a fuel cell humidifier corresponding to the method described in the above-mentioned embodiment 1 or 2, comprising a parameter acquisition unit, a data analysis and prediction module, and a prediction result output unit connected in sequence.

[0123] The parameter acquisition unit is used to obtain the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the current moment and send it to the data analysis and prediction module.

[0124] The data analysis and prediction module is used to establish the input of the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier, and the output is the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier, including the wet side orifice coefficient C of the humidifier. r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, and heat transfer coefficient U as the humidifier physical model for parameters to be calibrated; obtain the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier, and determine the above-mentioned parameters to be calibrated in the humidifier physical model; obtain the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the current moment, input them into the humidifier physical model after the parameters to be calibrated are determined, and obtain the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier, and send them to the prediction result output unit.

[0125] The prediction result output unit is used to display the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the previous moment, as well as the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier.

[0126] While various embodiments of the present disclosure have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements over the prior art, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for predicting the humidification capacity of a fuel cell humidifier, characterized in that: include: The input is the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier, and the output is the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier, including the wet side orifice coefficient C of the humidifier. r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, heat transfer coefficient U as the physical model of the humidifier to be calibrated; Obtaining test data of gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier, and determining the above-mentioned parameters to be calibrated in the humidifier physical model; Obtain the real-time data of the gas state parameters at the inlet of the dry side and the wet side of the humidifier at the current moment, input it into the humidifier physical model after the calibration parameters are determined, and obtain the predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier; The gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier include gas flow, gas temperature, gas pressure, and gas humidity; The following steps are also included to verify the correctness of the humidifier physical model: After the parameters to be calibrated in the humidifier physical model are determined, new test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier are obtained again; The new test data of the gas state parameters at the inlet of the dry side and the wet side are input into the humidifier physical model after the calibration parameters are determined, and new predicted data of the gas state parameters at the outlet of the dry side and the wet side of the humidifier are obtained; Identifying whether the new predicted data of the gas state parameters at the outlets of the dry side and the wet side of the humidifier are consistent with the corresponding new experimental data of the gas state parameters at the outlets of the dry side and the wet side, so as to determine the correctness of the humidifier physical model; The step of obtaining test data of gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier further includes: A gas flow meter, a gas temperature sensor, a gas pressure sensor, and a gas humidity sensor are respectively arranged on the inner walls of the input and output pipes on the dry and wet sides of the humidifier; A bench test is conducted on the humidifier equipped with the above-mentioned sensors to obtain the gas flow rate, gas temperature, gas pressure, and gas humidity at the inlet and outlet of the dry side and wet side of the humidifier, respectively, as the test data of the gas state parameters at the inlet and outlet of the dry side and wet side of the humidifier; The humidifier physical model includes: in, h in1 =c p ·T in1 ,h in2 =c p ·T in2 h out1 =c p ·T out1 ,h out2 =c p ·T out2 h tr =c p ·[1 / 2(T in2 +T out2 )-1 / 2(T out1 +T in1 )] u1=c v ·T in1 u2=c v ·T in2 W1=W in1 -W out1 +W vap,tr W2=W in2 -IN out2 -IN vap,tr ΔT=1 / 2[(T in2 +T out2 )-(T out1 +T in1 )] Where W out1 is the gas flow prediction data at the dry side outlet of the humidifier, W in1 is the real-time data of gas flow at the dry side inlet of the humidifier, W out2 is the gas flow prediction data at the wet side outlet of the humidifier, W in2 is the real-time data of gas flow at the wet side inlet of the humidifier, h tr is the gas enthalpy of water vapor, is the heat transferred from the wet side to the dry side, W vap,tr is the water vapor mass transfer, W1 is the dry side gas flow, W2 is the wet side gas flow, c p is the specific heat capacity of gas at constant pressure, c v is the constant volume specific heat capacity of gas, m is the gas mass, U is the heat transfer coefficient, A hum is the total membrane area of ​​the humidifier, ΔT is the temperature difference between the dry side and the wet side, M vap is the molar mass of water vapor, D is the mass transfer coefficient, C r_s is the wet side orifice coefficient, C r_t is the dry side orifice coefficient, C s is the wet side water concentration, C t is the water concentration on the dry side, ρ is the density of the membrane, M mem is the equivalent mass of the proton exchange membrane, λ1 is the water content on the dry side, λ2 is the water content on the wet side, t mem is the thickness of the proton exchange membrane, a1 is the predicted data of gas humidity at the dry side outlet of the humidifier, a2 is the predicted data of gas humidity at the wet side outlet of the humidifier, T in1 is the real-time data of gas temperature at the dry side inlet of the humidifier, T in2 is the real-time data of gas temperature at the wet side inlet of the humidifier, T out1 is the predicted data of gas temperature at the dry side outlet of the humidifier, T out2 is the predicted data of gas temperature at the wet side outlet of the humidifier, P in1 is the real-time data of gas pressure at the dry side inlet of the humidifier, P in2 is the real-time data of gas pressure at the wet side inlet of the humidifier, P out1 is the predicted data of the air pressure at the dry side outlet of the humidifier, P out2 is the predicted data of air pressure at the wet side outlet of the humidifier, P sub1 The preset pressure of the air entering the pile, P sub2 The preset pressure of the air leaving the stack, P vap1 is the water vapor pressure at the dry side outlet of the humidifier, P vap2 is the water vapor pressure at the wet side outlet of the humidifier, P sat1 is the saturated vapor pressure corresponding to the gas temperature at the dry side outlet of the humidifier, P sat2 is the saturated water vapor pressure corresponding to the gas temperature at the wet side outlet of the humidifier, V1 is the volume of the dry side of the humidifier, V2 is the volume of the wet side of the humidifier, n1 is the amount of water vapor substance on the dry side of the humidifier, n2 is the amount of water vapor substance on the wet side of the humidifier, R is the ideal gas constant, P sat_in1 is the saturated vapor pressure corresponding to the gas temperature at the dry side inlet of the humidifier, P sat_in2 RH is the saturated vapor pressure corresponding to the gas temperature at the wet side inlet of the humidifier, in1 The real-time data of gas humidity at the dry side inlet of the humidifier, RH in2 Real-time data of gas humidity at the wet side inlet of the humidifier, t is the current time, t deltat For the previous moment; The step of obtaining the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier, and determining the parameters to be calibrated in the physical model of the humidifier further includes: Obtain the gas flow rate, gas temperature, gas pressure, and gas humidity at the inlet and outlet of the dry side and the wet side of the humidifier as the gas state parameter test data at the inlet and outlet of the dry side and the wet side of the humidifier; The determination is based on the gas state parameter test data at the inlet and outlet of the dry side and wet side of the humidifier as input, and includes the wet side orifice coefficient C r_s , Dry side orifice coefficient C r_t , mass transfer coefficient D, heat transfer coefficient U to be calibrated parameters of the humidifier humidification capacity objective function model; The iterative change rule of each of the above-mentioned parameters to be calibrated is set, and the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier are brought into the above-mentioned humidifier humidification capacity objective function model for iteration until the parameters to be calibrated that minimize the output value of the humidifier humidification capacity objective function model are obtained.

2. The method for predicting the humidification capacity of a fuel cell humidifier according to claim 1, wherein: The humidifier humidification capacity objective function model includes: y(C r_t ,C r_s ,D,U) =sqrt{[W out10 -W out1 (C r_t ,C r_s ,D,U)] 2 +[W out20 -W out2 (C r_t ,C r_s ,D,U)] 2 +[P out10 -P out1 (C r_t ,C r_s ,D,U)] 2 +[P out20 -P out2 (C r_t ,C r_s ,D,U)] 2 +[a 10 -a1(C r_t ,C r_s ,D,U)] 2 +[a 20 -a2(C r_t ,C r_s ,D,U)] 2 +[T out10 -T out1 (C r_t ,C r_s ,D,U)] 2 +[T out20 -T out2 (C r_t ,C r_s ,D,U)] 2 } Where, y(C r_s , C r_t , D, U) is the objective function, W out10 is the gas flow test data at the dry side outlet, W out1 (C r_s , C r_t , D, U) is the gas flow prediction data at the dry side outlet obtained by the humidifier physical model, W out20 is the test data of gas flow rate at wet side outlet, W out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas flow rate obtained by the humidifier physical model, P out10 is the gas pressure test data at the dry side outlet, P out1 (C r_s , C r_t , D, U) is the dry side outlet gas pressure prediction data obtained by the humidifier physical model, P out20 is the wet side outlet gas pressure test data, P out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas pressure obtained by the humidifier physical model, a 10 is the test data of gas humidity at the dry side outlet, a1(C r_s , C r_t , D, U) are the predicted data of gas humidity at the dry side outlet obtained by the humidifier physical model, a 20 is the test data of gas humidity at the wet side outlet, a2(C r_s , C r_t , D, U) are the predicted data of wet side outlet gas humidity obtained by the humidifier physical model, T out10 is the test data of gas temperature at the dry side outlet, T out1 (C r_s , C r_t , D, U) is the predicted data of gas temperature at the dry side outlet obtained by the humidifier physical model, T out20 is the test data of wet side outlet gas temperature, T out2 (C r_s , C r_t , D, U) are the predicted data of wet side outlet gas temperature obtained by the humidifier physical model, and sqrt{} is the square root function.

3. The method for predicting the humidification capacity of a fuel cell humidifier according to claim 2, wherein: The step of setting an iterative change rule for each of the above parameters to be calibrated, bringing the test data of the gas state parameters at the inlet and outlet of the dry side and the wet side of the humidifier into the above humidifier humidification capacity objective function model and iterating until the parameter to be calibrated that minimizes the output value of the humidifier humidification capacity objective function model is obtained further includes: Set the initial values ​​of all parameters to be calibrated, the change range of each iteration, and the maximum number of iterations; The gas state parameter test data at the dry side and wet side inlet of the humidifier are brought into the humidifier physical model with the parameters to be calibrated, and the gas state parameter prediction data at the dry side and wet side outlet of the humidifier are obtained in each iteration; The predicted data of the gas state parameters at the dry side and wet side outlets of the humidifier and their corresponding test data are respectively input into the humidification capacity objective function model of the humidifier containing the above parameters to be calibrated for iterative calculation; Identify whether the absolute value of the difference between the objective function of the previous and next iterations is less than or equal to the set precision, or the number of iterations is greater than or equal to the maximum number of iterations. If so, stop the iteration and execute the next step. Otherwise, continue the iteration. Obtain the smaller value of the two objective functions at the time of stopping iteration, and use the corresponding undetermined parameter value as the final calibrated undetermined parameter value.

4. The method for predicting the humidification capacity of a fuel cell humidifier according to claim 3, wherein: The setting accuracy is 10 -3 Above, the maximum number of iterations is 10 -4 above.

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